text: #!/usr/bin/env python3
  # Copyright (c) 2016-2019 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Encode and decode BASE58, P2PKH and P2SH addresses."""
  
  from .script import hash256, hash160, sha256, CScript, OP_0
  from .util import hex_str_to_bytes
  
  from . import segwit_addr
  
  chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
  
  def byte_to_base58(b, version):
      result = ''
      str = b.hex()
      str = chr(version).encode('latin-1').hex() + str
      checksum = hash256(hex_str_to_bytes(str)).hex()
      str += checksum[:8]
      value = int('0x'+str,0)
      while value > 0:
          result = chars[value % 58] + result
          value //= 58
      while (str[:2] == '00'):
          result = chars[0] + result
          str = str[2:]
      return result
  
  # TODO: def base58_decode
  
  def keyhash_to_p2pkh(hash, main = False):
      assert len(hash) == 20
      version = 0 if main else 111
      return byte_to_base58(hash, version)
  
  def scripthash_to_p2sh(hash, main = False):
      assert len(hash) == 20
      version = 5 if main else 196
      return byte_to_base58(hash, version)
  
  def key_to_p2pkh(key, main = False):
      key = check_key(key)
      return keyhash_to_p2pkh(hash160(key), main)
  
  def script_to_p2sh(script, main = False):
      script = check_script(script)
      return scripthash_to_p2sh(hash160(script), main)
  
  def key_to_p2sh_p2wpkh(key, main = False):
      key = check_key(key)
      p2shscript = CScript([OP_0, hash160(key)])
      return script_to_p2sh(p2shscript, main)
  
  def program_to_witness(version, program, main = False):
      if (type(program) is str):
          program = hex_str_to_bytes(program)
      assert 0 <= version <= 16
      assert 2 <= len(program) <= 40
      assert version > 0 or len(program) in [20, 32]
      return segwit_addr.encode("bc" if main else "bcrt", version, program)
  
  def script_to_p2wsh(script, main = False):
      script = check_script(script)
      return program_to_witness(0, sha256(script), main)
  
  def key_to_p2wpkh(key, main = False):
      key = check_key(key)
      return program_to_witness(0, hash160(key), main)
  
  def script_to_p2sh_p2wsh(script, main = False):
      script = check_script(script)
      p2shscript = CScript([OP_0, sha256(script)])
      return script_to_p2sh(p2shscript, main)
  
  def check_key(key):
      if (type(key) is str):
          key = hex_str_to_bytes(key) # Assuming this is hex string
      if (type(key) is bytes and (len(key) == 33 or len(key) == 65)):
          return key
      assert False
  
  def check_script(script):
      if (type(script) is str):
          script = hex_str_to_bytes(script) # Assuming this is hex string
      if (type(script) is bytes or type(script) is CScript):
          return script
      assert False
  